Driving and supporting means for high speed printing drum



y 1966 c. A. CHRISTOFF ET AL 3,253,539

DRIVING AND SUPPORTING MEANS FOR HIGH SPEED PRINTING DRUM 4 Sheets-Sheet 1 Filed Sept. 16, 1963 A TTOE/Vi) y 1966 c. A. CHRISTOFF ET AL 3,253,539

DRIVING AND SUPPORTING MEANS FOR HIGH SPEED PRINTING DRUM 4 Sheets-Sheet 2 Filed Sept. 16, 1963 PIE Q r mm H M75 m m w I M a A MD Z ww May 31, 1966 c. A. CHRISTOFF ET AL 3,253,539

DRIVING AND SUPPORTING MEANS FOR HIGH SPEED PRINTING DRUM Filed Sept. 16, 1963 E l L:L CI:

4 Sheets-Sheet 5 INVENTOR, ore/s A. (HP/3701) JOHA/ 0. 62715175467 BY Z1? /44 A TTGE/l/E Y c. A. CHRISTOFF ET AL 3,253,539

May 31, 1966 DRIVING AND SUPPORTING MEANS FOR HIGH SPEED PRINTING DRUM 4 Sheets-Sheet 4 Filed Sept. 16, 1963 INVENTOR. OVF/J A. WE/S701? JO/M/ Q GE/lEf/EAET ATTOE/VEY REVERSIBLE POWER SUPPLY COUNTER COMPARISON GATE BUFFER STORAGE.

United States Patent 3,253,533 DRIVING AND SUPPDRTING MEANS FUR HIGH SPEED PRENTING DRUM Chris A. Christofi, San Gabriel, and John ]D. Gearheart,

Covina, Calif., assignors to Gary Corporation, San

Gabriel, Calif., a corporation of California Filed Sept. 16, 1963, Ser. No. 308,937 Claims. (Cl. 101-933) This invention relates to high speed data printers of the type incorporating a rotating type drum having a plurality of peripheral columns of type elementsthereon. A printing hammer is provided to effect an imprint of a selected type character in one column and is then shifted to effect an imprint of a selected type character in the next column, etc. Data to be printed is represented by coded signals obtained from a computer, register or the like. Such data is compared with coded signals representing the different type elements as such elements pass under the printing hammer. When a match is obtained the hammer is actuated to imprint the selected character on a record medium.

A principal object of the present invention is to provide a high speed printer of the above type which is portable, highly compact and adapted to be manufactured in a relatively light and small package.

Another object is to provide a printer of the above type which is reliable, rugged, and yet inexpensive to manufacture and service.

The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a front view, with parts broken away, of a printer embodying a preferred form of the present invention.

FIG. 2 is a transverse sectional view taken line 2-2 of FIG. 1.

FIG. 3'is a transverse sectional view taken along the line 3-3 of FIG. 1, illustrating part of the paper advancing mechanism.

FIG. 4 is a sectional plan view taken along line 44 of FIG. 1, illustrating the type hammer escapement mechanism.

FIG. 5 is an enlarged sectional plan view taken substantially along the line 55 of FIG. 3, illustrating part of the hammer actuating mechanism.

FIG. 6 is a sectional view taken substantially along the line 66 of FIG. 3.

FIG. 7 is a transverse sectional view illustrating part of the type hammer shifting mechanism and is taken substantially along the line 7-'7 of-FIG. 1.

FIG. 8 is an enlarged transverse sectional View taken substantially along the line 8-8 of FIG. 1, illustrating the printing ribbon advancing mechanism.

FIG. 9 is a schematic view illustrating the basic circuit connections for the printer.

Referring to the drawings, the printer comprises a frame including end walls 11 and 12 and a back side wall 13.

along the A supply roll 14 of paper 9 is carried on a suitable After passing over the.

3,253,539 Patented May 31, 1966 "ice tending rows and in circumferentially extending columns. Preferably, the type characters are identical in each row and progress in value around each column.

The drum is hollow and is rotatably mounted at its leftlatter is attached to the wall 12 and carries at its lefthand end the stator portion of an electric motor located within the type drum. The rotor of the motor carries a rotatable drive shaft 26 at the lefthand end of .the motor to which is attached a metal hub member 27 fitted Within the type drum and held in driving relation with the drum by a spring pressed drive key 28 which normally fits in a keyway 30 in the drum. The hub 27 thus supports the lefthand end of the motor within the drum.

The bracket 22 has an inwardly projecting extension 31 on which are mounted a pair of electric'induction pick-up heads 32 and 33 of conventional construction. The hub member 27 is provided with a series of equally spaced segments 34 which are angularly spaced to generate a pulse in the head 32 each time a new row of type characters pass a printing point P. As shown, the type drum is constructed to print numerals from 0 to 9. However, the drum could equally well be constructed to print alpha-numerical characters and others, in which case the hub member would be divided into a correspondingly larger number of segments.

A metal reset pulse generating arm 35 is attached to the motor shaft 26 and generates a pulse in the pick-up head 33 each time the drum makes a complete revolution.

It will be noted that the drum, being formed of metal, performs the additional function of shielding the motor and pick-up heads from emitting electromagnetic radiations which might cause radio transmission interference.

The paper is provided with perforations 36 along the opposite edges thereof which are engaged by pins 37 carried by sprocket rings 38 and 39 rotatably mounted on the type drum at opposite ends thereof. The sprocket rings are of slightly larger outer diameter than the type drum 16 so that the paper 9 is normally held out of contact with the type characters on the drum.

The sprocket rings are normally held stationary and are incrementally advanced to line space the paper by an advancing mechanism generally indicated at 40, FIGS. 3 and 6, which is basically similar to that disclosed and claimed in the US. patent to R. E. Busch, No. 3,138,961, issued on June 30, 1964, to which reference may be had for a complete-disclosure of such mechanism.

Generally, the mechanism 40 comprises a gear 141 rotatably mounted on a stationary rod 142 and meshing with the gear 45 of the sprocket ring 39. The gear 141 has integrally formed thereon a sleeve 143 which is also rotatably about the rod 142 and has mounted at its opposite end a second gear (not shown) similar to gear 41 for driving the sprocket ring 38 in timed relationship with ring 39. A suitable spring detent device (not shown) is provided to detent the gear 141 in different positions corresponding to the line spacing of the paper.

The gear 141 has a series of equally spaced radially extending V-shaped teeth 144 which mate with identical teeth 145 formed on a pawl element 46, also rotatably mounted on the rod 142. The pawl element has a second set of radially extending V-shaped teeth 47 which are of coarser pitch than the teeth 145 and which mate with identically shaped teeth on a wedging element 48 also rotatably mounted on the rod 142. A sleeve Stl limits rightward movement of the wedging element.

The sides of the teeth 47 preferably extend at substantially the same angle to the axis of the rod 142 as the teeth 144- and 145.

The pawl 46 is continuously oscillated about the rod 142 an amount equal to the pitch of the teeth 145 and 146 and for this purpose it is provided with an arm 51 pivotally connected by a link 52, FIG. 3, to a cam follower 54. The latter is fixed on a rock shaft 55 and carries rollers 56 which cooperate with a pentagon-shaped cam 57 driven continuously by the type drum through a gear 146 attached to a shaft 147 carrying the cam. The gear 146 meshes with a gear 148 integral with the drum 16.

The wedging element 48 is normally held in a noneffective position, shown in FIGS. 3 and 6, under the influence of a stationary permanent magnet 58 through a pair of soft iron extensions 69 which are normally engaged by a soft iron armature 61 integral with the wedging element, against the action of a tension spring 62. In this condition, oscillation of the pawl element 46 will result in an idling movement in which the pawl will merely float axially a slight amount during its rocking movement without transferring movement to the gear 141.

Upon momentarily energizing a pair of coils 63 on the magnet extensions 60, as will be described later, the magnetic flux exerted by the magnet 58 will be overcome permitting the spring 62 to rock the wedging element 48 counterclockwise (FIG. 3) to cam the pawl element 46 leftwardly so as to mesh the teeth 44 and 45 together. Thus, upon the following oscillation of the pawl, the gear 141 will be driven to advance the sprocket rings 38 and 39 and paper one line space. During the return movement of the parts, the wedging element will be returned to its position of FIG. 3 wherein the armature 61 will again engage the extensions to again retain the wedging element in non-effective condition.

Means are provided for serially transferring imprints of selected type characters from the type drum 16 to the paper and for this purpose a hammer device generally indicated at 66, FIGS. 1 and 2, is provided.

The hammer is of relatively light mass and comprises a pair of thin spaced arms 67 slideable along a tubular shaft 68 which is supported for rocking movement in bearings formed in the end frame plates 11 and 12. Each arm has a key formation 168 which is movable along a mating longitudinally extending slot in the tube. The arms 67 are held in spaced relation to their upper ends by a platen piece 70 which is effective to transfer an imprint to the paper during counterclockwise rocking of the hammer.

An endless ribbon 71 is wrapped over an idler roller '72, rotatably supported between the upper ends of the arms 6'] and an inking impregnated roller 73 of felt or the like. The latter is carried by a sleeve '74 rotatably mounted on the shaft 68 and provided with a ratchet wheel 75 which is incrementally advanced to advance the printing ribbon past the platen piece 70. For this purpose, the ratchet wheel is engaged by a blade 76 extending along the length of the drum 16. The blade is mounted at its ends on leaf springs 77 carried by levers 78 which are pivotally supported at 80 on the end Walls 11 and 19. The latter levers are pivotally connected to hell cranks 82 pivotally supported on the shaft 68 and are connected by inks 83 to arms 84 suitable fastened to the oscillating shaft 55 whereby to cause oscillation of the blade 76 about the pivot supports 80 to incrementally advance the roller 73 and printing ribbon 71.

Means are provided under control of differently timed pulses to oscillate the tubular shaft 68, causing the hammer device 66 to effect imprints of selected type characters on the drum 16 as they pass the printing point P. For this purpose, a selectively operable oscillating drive unit generally indicated at 85, FIGS. 3 and 5, is provided. The latter is basically similar to the mechanism described 4- and claimed in the copending application of R. E. Busch, SN. 286,612, filed June 10, 1963 and it will therefore be only briefly described herein.

The drive unit 85 comprises a wedge disc 86, a driving disc 87 and a driven disc 88, all mounted in side by side relation on the oscillating shaft 55. Retainer disc 90 and 91 are secured on the shaft on opposite ends of the discs 86 and 88 to limit axial movement of the latter.

The adjacent faces of the discs 86 and 87 are provided with intermeshing, radially extending V-shaped teeth 92. Likewise, the adjacent faces of the discs 87 and 88 are formed with intermeshing V-shaped teeth 93 similar to the teeth 92.

The driving disc 87 is suitably keyed in a manner not shown to the shaft 55 whereby it is constrained to oscillate with the shaft but is free to move axially a slight amount. The driven disc 88 has an arm 94 thereon which is connected by a link 95 to an arm 96 fastened to the tube 68. The wedging disc 86 has a soft iron armature 97 integral therewith which cooperates with a stationary permanent magnet 98 through soft iron extensions 100 to normally hold the wedging disc in a counterclockwise rocked position, as shown in FIG. 3, against the action of a tension spring 101. In such position of the disc 86, it will be ineffective to wedge the driving disc into driving engagement with the driven disc and therefore the driving disc will merely oscillate in an idle manner in sliding engagement with the teeth of the discs 86 and 88, during which time it will float axially under the camming effect of the teeth on the discs 86 and 88. However, upon energization of a pair of coils 102 wound on the extensions 100, the magnetic flux developed by the magnet 98 is counteracted, permitting spring 101 to urge the wedging disc clockwise to wedge the driving disc into driving engagement with the driven disc whereby to oscillate the tubular shaft 68 and thereby cause the hammer 66 to impinge against the paper so as to print an image of the type character passing immediately thereunder.

The print pulse applied to the coils 102 is only momentary and therefore as the shaft 55 returns the various discs 86, 87 and 88 to their counterclockwise rocked positions the armature 97 will again engage the extensions 100 where they will be magnetically latched against the action of spring 101.

As an incident to each printing operation of the hammer, it is letter spaced to the right to align with the next column of type characters on the drum. For this purpose, one of the hammer arms 67 has a depending bifurcated pawl extension 103, the legs of which cooperate with a pair of stationary toothed escapement racks 104 and 105 (FIG. 4) suitably mounted, in a manner not shown, on the machine frame.

Means are provided for moving the hammer unit to the right when released from the escapement teeth and comprises a reversible direct current drive motor 106 which drives a belt pulley 107 through a friction slip clutch 108. An endless belt 110 is wrapped over the pulley 107 and one strand thereof is guided over a guide pulley 111 and through the tube 68 where it is attached at 112'(FIG. 2) to the key formed on one of the hammer arms 67. This strand of the belt passes around the tension pulley 113 carried on an arm 114 pivotally supported at 115 and urged counterclockwise by tension spring 116. The second strand of the belt extends through the bifurcated portion of the hammer extension 103 and is guided over a second guide pulley 117 onto the drive pulley.

When the hammer unit is actuated to effect a printing impression, the pawl extension 103 recedes from engagement with an adjacent tooth on the escapement rack 104 and moves into blocking relation with an adjacent escapement tooth on the rack 105. It will be noted that the teeth of the two racks 104 and 105 are out of line with each other so that the hammer will be advanced approximately one-half the distance between two adjacent columns of type characters and will be aligned adjacent one of such columns just prior to the printing impression. Thereafter, as the hammer is returned to its normal position as shown in FIG. 2, the pawl extension 103 recedes from the rack 105 and again limits against the next adjacent tooth on the rack 104 under the pull of belt 110.

When the hammer reaches its righthand limit position, it closes a normally open switch 118, FIG. 9 thus completing a circuit to the aforementioned coils 63 to efi ect a paper advance and at the same time sets a bistable switch unit 120 to cause reversal of a direct current power supply 130 for the motor 106. Accordingly, the motor will drive the belt 110 a reverse direction to shift the hammer unit to its lefthand position where it will close a second normally open switch 131. The latter will reset the bistable unit 120 to cause a reversal of motor 106 to again urge the hammer to the right into its first printing position.

As stated hereinbefore, the inductive pick-up head 32 generates a pulse each time a row of type characters on the drum pass the printing point P. Such pulses are fed to a counter 132 whose output indicates the value of each of the type characters passing the printing point at the moment. The output of the counter 132 is applied to a comparison gate 133 of conventional construction where it is compared With the output of a register 134 containing the data to be printed. When the output of the counter matches the value registered by the register 134, a pulse is applied over line 135 to energize the coils 102 and thus effect a printing operation.

Reset head 33 generates a pulse at the start of each revolution of the drum and is effective to reset the counter 132 to therefore assure that the counter is in time with the drum.

Although the invention has been described in detail and certain specific terms and languages have been used, it is to be understood that the present disclosure is illustrative rather than restrictive and that changes and modifiications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what is desired to be secured "by United States Letters Patent is:

1. Printing mechanism comprising the combination of a hollow type drum having a plurality of difierent type characters therearound, a frame, a stationary arbor supported 'by said frame, means on said arbor rotatably supporting said drum adjacent one end of said drum, a

motor within said drum and supported at one end by said arbor, said motor having a drive shaft at the opposite end thereof, a drive member mounted on said shaft, means attaching said drive member to said drum internally of said drum whereby to rotate said drum and to support said motor at said opposite end of said motor, means on said frame rotatably supporting said drum adjacent the opposite end of said drum, said drum being formed of material effective to prevent transmission of electromagnetic radiation therethrough from said motor, means for guiding a record medium past said drum, and means for recording images of selected ones of said type characters onto said record medium.

2. Printing mechanism comprising the combination of a hollow type drum having a plurality of different type characters therearound, a stationary arbor, means on said arbor rotatably supporting said drum adjacent one end of said drum, a motor within said drum and supported at One end by said arbor, means forming a driving connection between said motor and said drum whereby to rotate said drum, a second stationary arbor, means on said second ar bor rotatably supporting said drum adjacent the opposite end of said drum, a commutating device within said drum and driven by said motor, pulse generatingmeans carried by said second arbor and cooperating with said commutating device for generating pulses in time with movement of said type characters past a printing point, and means controlled by said pulse generating means for recording images of selected ones of said type characters onto said record medium.

3. A printing mechanism comprising the combination of a hollow type drum having a plurality of different type characters therearound, a stationary arbor, means on said arbor rotatably supporting said drum adjacent one end of said drum, a motor within said drum having a stator portion and a rotor portion; means on said arbor supporting said stator portion adjacent one end of said motor, means attaching said rotor portion to said drum adjacent the opposite end of said motor, means for rotatably supporting the opposite end of said drum, means for guiding a record medium past said drum, and means for recording images of selected ones of said type characters on said record medium.

4. Printing mechanism comprising the combination of a hollow drum having a plurality of different type characters therearound, a stationary arbor, means on said arbor rotatably supporting one end of said drum, a motor within said drum having a rotor and a stator, means securing said stator at one end of said motor to said arbor, means connecting said rotor at the opposite end of said motor to said drum whereby to rotate said drum, a second stationary arbor, means on said second arbor rotatably supporting the opposite end of said drum, a commutating device within said drum and driven by said rotor, pulse generating means carried by said second arbor and extending within said drum, said pulse generating means cooperating with said commutator for generating pulses in time with the movement of said type characters past a printing point, and means controlled by said pulse generating means for recording images of selected ones of said type characters onto said record medium.

5. The combination according to claim 3 wherein the axis of said motor extends coincident with the axis of said drum.

References Cited by the Examiner UNITED STATES PATENTS 2,536,679 1/1951 Fay 101248 2,714,850 8/1955 Kistner 10196 2,910,936 11/1959 Christoif et al. 10193 2,915,967 12/1959 Gehring'et al. 10193 2,915,968 12/1959 Witt et al. 10193 3,058,415 10/196'2 Hoifmann 10193 3,062,350 11/1962 Demmel 19717 3,090,299 5/1963 Comstock 101-100 WILLIAM B. PENN, Primary Examiner. 

1. PRINTING MECHANISM COMPRISING THE COMBINATION OF A HOLLOW TYPE DRUM HAVING A PLURALITY OF DIFFERENT TYPE CHARACTERS THEREAROUND, A FRAME, A STATIONARY ARBOR SUPPORTED BY SAID FRAME, MEANS ON SADI ARBOR ROTATABLY SUPPORTING SAID DRUM ADJCENT ONE END OF SAID DRUM, A MOTOR WITHIN SAID DRUM AND SUPPORTED AT ONE END BY SAID ARBOR, SAID MOTOR HAVING A DRIVE SHAFT AT THE OPPOSITE END THEREOF, A DRIVE MEMBER MOUNTED ON SAID SHAFT, MEANS ATTACHING SAID DRIVE MEMBER TO SAID DRUM INTERNALLY OF SAID DRUM WHEREBY TO ROTATE SAID DRUM AND TO SUPPORT SAID MOTOR AT SAID OPPOSITE END OF SAID MOTOR, MEANS ON SAID FRAME ROTATABLY SUPPORTING SAID DRUM ADJACENT THE OPPOSITE END OF SAID DRUM, SAID DRUM BEING FORMED OF MATERIAL EFFECTIVE TO PREVENT TRANSMISSION OF ELECTROMAGNETIC RADIATION THERETHROUGH FROM SAID MOTOR, MEANS FOR GUIDING A RECORD MEDIUM PAST SAID DRUM, AND MEANS FOR RECORDING IMAGES OF SELECTED ONES OF SAID TYPE CHARACTERS ONTO SAID RECORD MEDIUM. 